The metering of chemicals into toilet systems imposes severe restrictions on the design of the equipment if it is to be independent of additional sources of power, be capable of operating consistently for long periods between service calls and be inexpensive. Methods which have been used hitherto comprise various ways of dissolving solid or liquid chemicals by direct contact with water which is used for flushing toilet systems and of emitting perfumes or deoderants into the atmosphere. Such systems produce inconsistent results because excessively high concentrations of chemicals are dissolved in the flushing water following initial charging of the systems and ineffectively weak solutions are produced toward the end of the charge life. Thus, for only a relatively short period in the life of any one charge is the optimum chemical concentration achieved.
The present invention seeks to provide a fluid pump which is suitable for use in overcoming or at least alleviating the above stated problem.